On April 19th, 2013, jQuery UK was hosted in Oxford and Nexedi was able to attend. Below you can find a quick roundup of what happened.
jQuery will for the near future be available in two branches. The 2.0 branch drops support for IE6,7,8, because the code necessary to support these browsers produced new errors when working with environments like Phonegap. The 1.9 branch will kept alive and maintained, so there will be a latest version of jQuery which can be used with legacy browsers. (Slides)
The strength of jQuery is not only its code, but also the community around it. (Slides)
Showed how Google is using Chrome Canary (experimental Chrome browser - download here) to analyse and improve performance. The presentation showed tricks like how to export waterfalls as JSON HAR (http archive) files and anaylze data in 3rd party applications or how to optimize for "first paint" (first content to be displayed) by flushing content to the browser before the whole page is created (Slides)
How to use Category Theory from mathematics for faster DOM manipulation. (Slides)
Talked about the problem in developing a large scale application (case study: SureChem) that must run on IE6/7/8 and how difficult it was to set up testing environments. Testing was done using Selenium and Jenkins, with the presentation outlining how to use both in setting up virtual machines for IE6/7/8 (Slides).
How to optimize building applications for mobile devices - from minification to using grunt (Slides).